CN113038831B

CN113038831B - Device for producing improved animal numbers

Info

Publication number: CN113038831B
Application number: CN201980074790.9A
Authority: CN
Inventors: G·斯莱德
Original assignee: Zazile Co
Current assignee: Zazile Co
Priority date: 2018-11-26
Filing date: 2019-11-22
Publication date: 2023-04-11
Anticipated expiration: 2039-11-22
Also published as: BR112021005640A2; US20220001202A1; GB2579224A; GB201819190D0; EP3886578A1; CN113038831A; WO2020109756A1; GB2579224A8

Abstract

A device for isolating a non-human animal from a sterilant. The apparatus (100, 200) defines a space for receiving a non-human animal (111, 204) and a shield (107, 201) for isolating a portion of the animal from a sterilant, such as radiation. Exposing only a specific portion of the animal to the sterilant results in a sterilized animal that is better suited for mating with other animals. When animals that have been sterilized with sterile insect technology are released, the technology is more efficient because the released animals are more suitable for mating with wild animals.

Description

Device for producing improved animal numbers

The present invention provides a device for producing improved animal numbers, in particular for sterilising improved animal numbers. A method for producing an improved number of animals is also provided.

Many animals, particularly insects, need to be controlled for their wild-type number for human welfare or other purposes. Such as public health hazards, such as disease-transmitting mosquitoes, and agricultural pests that cause crop losses.

One possible method of controlling animal numbers involves feeding and releasing large numbers of sterile males of the species. Once these sterile males are released into the field, they compete with wild males for mating. The number of wild female animals decreases over time as mating events involving sterile animals do not produce offspring. This may bring benefits related to the reduction of the number of plans. In the case of insects, this technique is known as "sterile insect technique" (SIT). Similar methods can also be used to control the number of other target animals, whether those animals transmit disease or damage crops.

Typically, when insects are fed SIT, such as Drosophila mediterranei (Ceratitisca pitata), they are sterilized using ionizing radiation during the pupal development stage. In a variation of SIT, sterilization can be achieved by chemical sterilants (chemosterilants) and/or application to different life stages of the animal.

The current typical industrial scale process is to sterilize thousands of pupae in batches, containing them in a container with a volume of about 1 liter. Sterilization may be achieved by subjecting pupae in said volume to ionizing radiation. Disadvantages of this method are the adverse effect of ionizing radiation on the insects, the reduced percentage of pupae becoming adults, and the suitability of the sterilized adults for their ability to successfully discover and mate with wild insects. This reduces the effectiveness and/or increases the cost of the technology, as more insects need to be raised and released to have the desired effect.

These problems typically exist in variations of SIT, including other sterilization methods and other similar techniques for controlling the number of other types of animals.

It is an object of the present invention to address one or more of these problems.

In a first aspect, the present invention provides a device for isolating a non-human animal from a sterilant comprising;

a space for accommodating a non-human animal, an

A protective cover for isolating a portion of the non-human animal contained in the space from the sterilant.

In many cases, for animals to be sterilized, only the genitalia of the animal need be exposed to the sterilization treatment. The presence of the protective cover allows the parts of the animal other than the genitals to be protected from the sterilization treatment of the animal. For example, a shield may protect the body of an animal from ionizing radiation. This avoids harmful effects of radiation on other body parts of the animal. When the animal has developed fully, this will provide an adult animal that is more suitable for mating with a wild population than an animal receiving comprehensive irradiation. The improved characteristics of the number of sterilised animals produced using the device mean that fewer animals need to be raised to have the same effect when the sterilised animals are released into the field. This may reduce the costs associated with the process and/or more effectively reduce the number of wildlife that needs to be controlled.

In the following, some embodiments described use (or devices used with) sterilization by radiation. This does not imply any limitation of the invention in other sterilization methods. Other sterilization methods may be used and the device of the present invention may be adapted for use with other sterilization methods.

The shield may be a radiation shield. In the case of sterilization by radiation, it is preferred that the radiation shield comprises a material that is substantially impermeable to ionizing radiation, such as lead. Preferably, the radiation shield blocks substantially all radiation (incident thereon) from passing through it. The percentage of radiation that needs to be blocked in order to achieve the most desirable results will depend on the species of animal with which the device or method is to be used. The preferred percentage of radiation blocked may also depend on the type of radiation used. In some embodiments, 20% to 95%, preferably 50% to 98%, of the incident radiation from a particular radiation source is blocked by the radiation shield.

The apparatus may include a plurality of spaces for accommodating the non-human animals, respectively. This allows for individualized, predictable and controllable radiation doses to be applied to each animal. It also avoids any effect associated with one animal blocking or refracting radiation that would otherwise be incident on another animal in a given container. The space may be a set of containers. The container may be formed as a microtiter plate.

The volume of the or each space may be no more than 0.001m ³ . The volume of the or each space may be less than 0.0001m ³ Or less than 0.00001m ³ . The volume of the or each space may be in the range 1.5 x 10 ^-8 m ³ To 3.6X 10 ^-7 m ³ Within the range of (1). In some embodiments, the sum of the sides (height + width + extent) of the or each space is no greater than 30cm, or no greater than 20cm, or no greater than 10cm. The width to length to depth ratio of the space defined by each well may be about 1.

The apparatus may further comprise means for moving the one or more spaces through radiation or a chemical sterilant. This allows the device to operate as a continuous process in which the radiation source or chemical sterilant source does not need to be turned on and off for discrete batches of animals.

The mechanism for moving the one or more spaces through the radiation or chemical sterilant may be a conveyor. The mechanism for moving the one or more spaces may follow a curved path. The path may be a linear or non-linear path extending in 2 or 3 spatial dimensions. For example, the path may be substantially circular (i.e. more than 2 dimensions), or the path may be a substantially spiral path (i.e. more than 3 dimensions). When the sterilant source emits the sterilant over a discrete volume, this allows the animal to surround the sterilant source rather than, for example, passing through a narrow directed beam. The one or more spaces may be formed as a container and may be shaped to contain the animal in an annular arrangement around the sterilant source.

The shield is preferably a radiation shield, which is positioned as close as possible to the animal to reduce refraction of incident radiation. Preferably, when an animal is accommodated in said space, the average distance between the animal and the wall defining the space is less than 1mm, less than 2mm, less than 5mm or less than 10mm.

The space may be elongated so as to limit movement of the non-human animal contained in the space. Many insect pupae have an elongated shape. In some embodiments, the elongate shape of the space is adapted to prevent inversion of a pupae once it is received in the space. This limitation of movement helps expose a portion of the animal to a predictable dose of the sterilant, which substantially affects only the portion of the animal that is sterilized. For insect pupae, the genitals are typically located near the ends of the elongate shape of the pupae. This allows the genitals to clearly protrude from the space shielded by the shield.

The apparatus may further comprise means for reducing the temperature within the space.

In some embodiments, the animal is exposed to a sterilant, e.g., ionizing radiation, for seconds or minutes. Preferably, it is assured that the animal will not substantially move during this period of time. This is particularly important because it is difficult to place a camera inside the device to check whether the animal has moved. The cooled space containing the animal can be used to hold the animal. This is particularly useful for fixing insects.

The space may allow free movement of the animal as long as the free movement does not affect the continued exposure of the desired site of the animal to the sterilant.

Other aspects of the space or measures taken with the animal may be adapted to immobilize the animal. These measures may include treatment of the animal, such as administration of a sedative.

The space may be formed in the shield cover. This allows for an integrated device. In some embodiments, this will facilitate manufacturing and reduce production costs, as the space may be formed in a single piece of material, for example by drilling a groove. The space may also be formed as a well. This allows the animal to be easily stored in the space without the need to remove the lid. It also allows the introduction of fluids or other materials into the space.

The space may be formed as a well and the protective cover may form a removable cover adapted to fit over the well. This enables easy filling of the space with animals. The lid is configured to also restrict the movement of the movable animal during the procedure. In embodiments comprising a number of spaces for accommodating animals, a cover is provided, enabling the protective cover to be applied to a number of spaces simultaneously. This saves time and provides a more efficient method. Providing the shield in the form of a cap may also reduce the manufacturing costs of the device. This is in contrast to an embodiment where the space is formed in one piece of protective material. Generally, for embodiments where the shield is configured as a cover rather than as a block providing space, less expensive shielding materials are required.

The space may contain a fluid. The fluid may float the animal in space, such as pupae, in order to optimize the position of the animal relative to the sterilant source. The position of the animal can be changed/optimized by adding or removing fluid to/from the space. Also, fluids may be necessary for the survival of animals. Cooling fluids, such as water, may also be used to reduce mobility of the animals.

The shield may be a radiation shield, and the apparatus may further comprise a source of ionizing radiation. The ionizing radiation source may produce X-rays, gamma rays, other electromagnetic radiation, or alpha particle radiation. When the radiation is irradiated to certain parts of the animal, the radiation provides a sterilization effect. The source of ionizing radiation and the radiation shield may be arranged such that only a selected part of the non-human animal accommodated in the space is exposed to the radiation. In a preferred embodiment, only the genitalia of the animal are exposed to ionizing radiation. The size, shape and configuration of the radiation shield will vary depending on the animal used.

The device may include a source of chemical sterilant. The source of chemical sterilant and the protective cover may be arranged such that only a selected portion of the non-human animal contained in the space is exposed to the chemical sterilant. The chemical sterilant may be administered to the non-human animal by immersing or partially immersing the non-human animal in the chemical sterilant.

In some embodiments, the shield is provided with an aperture through which radiation or chemical sterilant can act on an animal contained in the space.

In a second aspect, the present invention provides a device for exposing a portion of a non-human animal to a sterilant, comprising;

a body defining a space for receiving a non-human animal,

wherein the body is adapted to support the non-human animal in an orientation in the space that allows a portion of the non-human animal to be introduced into a bath of liquid sterilant without other portions of the non-human animal being exposed to the liquid sterilant.

The body may be formed from a mesh support. This allows the liquid sterilant to readily flow into the space and contact a portion of the non-human animal contained within the space. The body may be comprised of an array of wells, each well having an aperture that allows a sterilant to flow into the space and into contact with at least a portion of the non-human animal contained in the space. Preferably, the holes are located towards the lower end of each well. The apparatus may comprise one or more spaces having the features of one or more spaces described in connection with other aspects of the invention.

In a third aspect, the present invention provides a combination of a device according to the second aspect of the invention and a bath for containing a liquid sterilant.

In the combination, the bath may be filled with a sterilant when the non-human animal is present in the space and the device is stored in the bath, and the depth of the bath may be such that a portion of the non-human animal remains above the level of the sterilant even when the bath is filled with the sterilant. This provides a failsafe mechanism to ensure that parts of the non-human animal other than its genitals are not exposed to the sterilant due to overfilling the bath.

The device may be permanently connected to the bath. The apparatus may include a well, the lower end of which is open, so that a non-human animal placed in the well falls into the sterilant present in the bath. However, when the non-human animal falls into the sterilant, the walls of the well may still hold the non-human animal in a predetermined orientation, e.g., substantially upright. This means that only the genitalia of the animal are exposed to the sterilant.

In a fourth aspect, the invention provides a method of preparing a non-human animal for sterilization comprising the step of placing a non-human animal into a space of an apparatus according to the invention or a combination of the apparatus and a bath.

The method may include the further step of exposing a portion of the non-human animal to radiation or a chemical sterilant.

The non-human animal can be an arthropod. The non-human animal may be an insect. The non-human animal may be in any life stage, including egg, larval, pupal, or adult stages. The animal may be a rodent, such as a mouse.

The process may be carried out in a low temperature environment, for example at a temperature below 10 ℃.

In a fifth aspect, the present invention provides a technique of animal sterilization comprising the steps of subjecting a non-human animal to the sterilization method of the present invention, and releasing the non-human animal into the field. Preferably, the non-human animal is an insect.

The features of the apparatus of the invention and the combination of the apparatus and the bath may be incorporated into the method of the invention. The method of the invention may include the step of using any feature of the device of the invention or the combination of the device and the bath. Also, the device according to the invention or the combination of the device and the bath may incorporate features suitable for carrying out the method of the invention. Features from different aspects of the invention may also be combined.

Non-limiting embodiments of the present invention will now be described with reference to the accompanying drawings, in which:

fig. 1 shows a perspective view of a first embodiment of the present invention.

Figure 2 shows a side cross-sectional view of a pupa in combination with a radiation source housed in the device shown in figure 1.

Fig. 3 shows a perspective view of a second embodiment of the invention.

Figure 4 shows a cross-sectional view of a pupa in combination with a radiation source housed in the device shown in figure 3.

Figure 5 shows a cross-sectional elevation view of a first embodiment of a device and bath combination according to the invention.

Fig. 6 shows a cross-sectional side view of the embodiment shown in fig. 5.

Figure 7 shows a cross-sectional elevation view of a second embodiment of the device and bath combination according to the invention.

Fig. 8 shows a cross-sectional side view of the embodiment of fig. 7.

Fig. 1 shows an apparatus 100. The device comprises a tray 101 provided with ten wells 102. The volume of each well has a rectangular cross-section when viewed from above. Ten wells 102 form a linear array. Each well has a flat bottom 103 and an opening at the upper end. Each well has a depth 104, the depth 104 being greater than the width 105 of the well and greater than the length 106 of the well. Each well defines a volume having a width to length to depth ratio of about 1. The wells are arranged side-by-side such that each well is adjacent to two other wells except for the end well which is adjacent to only one well. The tray is made of a plastic material that is substantially transparent to ionizing radiation.

A radiation shield 107 is also provided. The radiation shield is in the shape of a hollow rectangular cube, which lacks its lower surface. The radiation shield is sized so that it can be removably fitted to the tray 101 along the path indicated by arrow 109. The depth 108 of the radiation shield is such that a lower portion of each well 102 protrudes from below the radiation shield when the radiation shield is fitted on the tray 101. This is shown more clearly in fig. 2, the radiation shield being made of lead, said shield being substantially impermeable to ionizing radiation.

Fig. 2 shows a side cross-sectional view of the device 100 shown in fig. 1 in combination with a radiation source 110. The pupa 111 is housed in the well of the device. Additional pupae (not shown) are individually contained in each of the other wells of the tray. A radiation shield 107 is mounted on the tray 101. The lower portion of the tray 112 protrudes from the lower end of the radiation shield.

The well contains water 113, and the pupae float in the water. In the illustrated device, the width and length of the well are not selected or arranged to prevent the elongate pupae from being inverted while in the well. In other embodiments, the width and length of the well are selected and arranged to prevent the elongate pupae from being inverted while in the well. The portion 114 of the pupa protruding from under the radiation shield comprises the genitals of the animal. The portion 115 of the pupa that does not protrude from the radiation shield comprises a body part of the animal other than the genitals.

The radiation source 110 is arranged such that when it is switched on, gamma-ray or X-ray radiation, represented by arrows in fig. 2, is emitted from the radiation source and is incident on the device 100. The radiation shield is arranged such that it shields the 115 part of the pupa from incident radiation. However, the lower portion 114 of the pupae is fully exposed to radiation, thereby sterilizing the animal.

Radiation was applied to the device and pupae for approximately one minute. The radiation source was then turned off, the pupae were removed from the wells and allowed to fully develop before release into the field.

Fig. 3 shows a device 200. The device comprises a cubic block 201 made of lead. The block has ten linear arrays of wells 202 formed by grooves in the top surface of the block. The well defines a volume having a circular cross-section when viewed from above. At the uphole end, there is a circular opening 203. The well has a constant cross-section over its height and is flat-bottomed. The height of the well is greater than the diameter of its opening.

Figure 4 shows a side cross-sectional view of a pupa 204 in combination with a radiation source 205 housed in the device 200 shown in figure 3. Other pupae (not shown) are individually received in each of the other wells of the block 201. The well 202 is sized to prevent pupae inversion. That is, the sides of the well 202 limit movement of the pupae so that the pupae are held in a generally upright orientation. The depth of the well 202 is arranged such that a portion 206 of the pupae protrudes through the opening 203 of the well 202. A portion 207 of the pupa does not protrude from the well. The portion 206 of the pupa protruding from the well comprises the genitals of the animal. There is substantially no fluid present in the well 202.

The radiation source 205 is arranged such that when it is switched on, gamma-ray or X-ray radiation, represented by arrows in fig. 4, is emitted from the radiation source and is incident on the device 200. The portion 206 of the pupae protruding from the well 202 is completely exposed to the radiation, while the portion 207 of the pupae contained within the well is shielded from the radiation by the lead block 201. A similar arrangement exists for other pupae, which are not shown in this view.

Radiation was applied to the device and pupae for approximately one minute. The radiation source is then turned off, the pupae are removed from the wells and allowed to fully develop before release into the field.

Fig. 5 shows a combination of a device 300, the device 300 being disposed in a bath 301 filled with a liquid sterilant 302. The device is formed by a thick wire mesh 303. The mesh is shaped to define an array of wells 304 having a square cross-section. There are ten wells in a linear array such that all wells share a well wall with adjacent wells. In other embodiments, the wells are arranged in a 2-dimensional array. Each well is sized to receive one pupae. The well is defined by vertical pillars 305 at each corner of the well and horizontal pillars 306 bridging the vertical pillars. The wells are elongated so that they can each hold an elongated pupae. The lower end of each well is provided with a stop (not shown) to prevent pupae from falling from the bottom of the well. The stop may be formed by a mesh defining the well.

Fig. 6 shows a pupa 307 placed in a well 304 of the device 300. In use, a pupae 307 is placed into each well 304 such that its genitals 308 are near the lower end of the well. This may be done when the device is not located in the bath. The device 300 is then lowered into a bath 301 containing a liquid sterilant 302. A suitable liquid sterilant is thiotepa. The level of the sterilization liquid in the bath is set such that when the device 300 is lowered into the bath or rests on the bottom of the bath by a predetermined amount, the pupae arranged in the well are only partially immersed in the sterilization liquid. The level of the sterilant is set so that usually only the genitalia of the pupae are immersed in the sterilant. The wells are arranged so that the remainder of the pupae in each well is above the level of the sterilant. This means that the sterilant has less effect on the characteristics of the pupae (except its reproductive capacity) than if the pupae were fully submerged. This will result in an improvement in insect population once the pupae develop to maturity.

Fig. 7 shows a second combination of a device 400 according to the invention and a bath 401. The device is formed from a coarse wire mesh 403. The mesh is shaped to define an array of wells 404 having a square cross-section. There are ten wells in a linear array such that all the wells share a well wall with adjacent wells. In other embodiments, the wells are arranged in a 2-dimensional array. Each well is sized to receive one pupae. The well is defined by vertical posts 405 at each corner of the well and horizontal posts 406 bridging the vertical posts. The wells are elongated so that they can each hold an elongated pupae. The walls of the well formed by the vertical pillars 405 extend into a bath 401 filled with a liquid sterilant 402. In other embodiments, the wire mesh does not extend into the bath but starts from a position where the bath walls end. The well in the device 400 does not have a separate stop at the lower end. The lower end of the well terminates at the bottom of bath 401.

Fig. 8 shows a pupa 407 placed in the well 404 of the device 400. In use, a pupae 407 is placed into each well 404 such that the genitals 408 of the pupae are proximate the lower end of the well. The device 400 is attached to a bath 401 so that, in use, pupae can be placed into the top of a well 404 and fall down into a disinfectant 402 present in the bath. The bath is filled to the rim with a sterilant. The depth of the bath is chosen so that usually only the genitals of the pupae, which are contained in the well, are immersed in the bath. The sterilant level does not rise to damage other parts of the pupae in the well because any additional sterilant added to the bath will spill directly over the sides of the bath and the sterilant level will not rise.

The wells are arranged so that the remainder of the pupae in each well is above the level of the sterilant. This means that the sterilant has less effect on the characteristics of the pupae (other than its reproductive capacity) than if the pupae were fully submerged. This will result in an improvement in insect population once the pupae develop to maturity.

Claims

1. A device for isolating a non-human animal from a sterilant comprising;

a space for accommodating a non-human animal, an

A shield for isolating a portion of the non-human animal contained in the space from the sterilant,

wherein the volume of the space is less than 0.0001m ³ 。

2. The apparatus of claim 1, wherein the shield is a radiation shield.

3. The apparatus of claim 1, wherein the apparatus comprises a plurality of spaces for respectively accommodating non-human animals.

4. The apparatus of claim 3, wherein a volume of each of the plurality of spaces is less than 0.0001m ³ 。

5. The apparatus of claim 4, wherein each of the plurality of spaces has a volume of less than 0.00001m ³ 。

6. The apparatus of claim 3, wherein each of the plurality of spaces has a volume of 1.5 x 10 ^-8 m ³ To 3.6X 10 ^-7 m ³ Within the range of (1).

7. The apparatus of claim 1, further comprising a mechanism for moving the space through radiation or chemical sterilant.

8. The apparatus of claim 7, wherein the mechanism for moving the space through radiation or chemical sterilant is a conveyor.

9. The apparatus of claim 7, wherein the mechanism for moving the space follows a curved path.

10. The device of claim 1, wherein the space is elongated so as to limit movement of a non-human animal contained in the space.

11. The apparatus of claim 1, further comprising a device for reducing the temperature within the space.

12. The device of claim 1, wherein the space is formed in the shield.

13. The apparatus of claim 1, wherein the space is formed as a well.

14. The device according to any one of claims 1-11, wherein the space is formed as a well and the protective cover forms a movable cover adapted to fit over the well.

15. The device of any one of claims 1-11, wherein the space comprises a fluid.

16. The apparatus of any one of claims 1-11, wherein the shield is a radiation shield and the apparatus further comprises a source of ionizing radiation.

17. The apparatus of claim 16, wherein the ionizing radiation source and the radiation shield are arranged such that only a selected portion of the non-human animal contained in the space is fully exposed to radiation.

18. The device of any one of claims 1-11, further comprising a source of chemical sterilant.

19. The apparatus of claim 18, wherein the source of chemical sterilant and the protective cover are arranged such that only a selected portion of the non-human animal contained in the space is exposed to the chemical sterilant.

20. The device of claim 1, wherein the volume of the space is less than 0.00001m ³ 。

21. The apparatus of claim 1, wherein the volume of the space is 1.5 x 10 ^-8 m ³ To 3.6X 10 ^-7 m ³ Within the range of (1).

22. A device for exposing a portion of a non-human animal to a sterilant comprising;

a body defining a space for housing a non-human animal,

wherein the body is adapted to orientate a non-human animal to be supported in the space, the orientation allowing a portion of the non-human animal to be introduced into a bath of liquid sterilant without other portions of the non-human animal being exposed to the liquid sterilant,

wherein the volume of the space is less than 0.0001m ³ 。

23. The device of claim 22, wherein the body is formed from a mesh support.

24. A combination of a device according to claim 22 or 23 and a bath for containing a liquid sterilant.

25. A combination according to claim 24, wherein the bath may be filled with a sterilant when a non-human animal is present in the space and the device is stored in the bath, and the depth of the bath is such that a portion of the non-human animal remains above the sterilant level even when the bath is filled with sterilant.

26. A method of preparing insects for sterilization comprising the step of placing said insects in said space of a device or combination according to any one of the preceding claims.

27. The method of claim 26, further comprising the step of exposing a portion of the insect to radiation or a chemical sterilant.

28. A method of sterilizing animals comprising the steps of:

i) Preparing a non-human animal for sterilization by placing the non-human animal into a space of an apparatus, the apparatus comprising:

a space for accommodating the non-human animal, an

ii) exposing a portion of the non-human animal to a sterilant; and

iii) Releasing the non-human animal into the field.